101
|
Kasimova MA, Yazici AT, Yudin Y, Granata D, Klein ML, Rohacs T, Carnevale V. A hypothetical molecular mechanism for TRPV1 activation that invokes rotation of an S6 asparagine. J Gen Physiol 2018; 150:1554-1566. [PMID: 30333107 PMCID: PMC6219692 DOI: 10.1085/jgp.201812124] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 08/13/2018] [Accepted: 09/26/2018] [Indexed: 12/13/2022] Open
Abstract
TRPV1 channels comprise four subunits containing six transmembrane segments (S1–S6) that surround a central pore. Kasimova et al. hypothesize that channel opening involves rotation of an S6 asparagine residue toward the pore, as well as associated pore hydration and external cavity dehydration. The transient receptor potential channel vanilloid type 1 (TRPV1) is activated by a variety of endogenous and exogenous stimuli and is involved in nociception and body temperature regulation. Although the structure of TRPV1 has been experimentally determined in both the closed and open states, very little is known about its activation mechanism. In particular, the conformational changes that occur in the pore domain and result in ionic conduction have not yet been identified. Here we suggest a hypothetical molecular mechanism for TRPV1 activation, which involves rotation of a conserved asparagine in S6 from a position facing the S4–S5 linker toward the pore. This rotation is associated with hydration of the pore and dehydration of the four peripheral cavities located between each S6 and S4–S5 linker. In light of our hypothesis, we perform bioinformatics analyses of TRP and other evolutionary related ion channels, evaluate newly available structures, and reexamine previously reported water accessibility and mutagenesis experiments. These analyses provide several independent lines of evidence to support our hypothesis. Finally, we show that our proposed molecular mechanism is compatible with the prevailing theory that the selectivity filter acts as a secondary gate in TRPV1.
Collapse
Affiliation(s)
- Marina A Kasimova
- Institute for Computational Molecular Science, Temple University, Philadelphia, PA
| | - Aysenur Torun Yazici
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ
| | - Yevgen Yudin
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ
| | - Daniele Granata
- Institute for Computational Molecular Science, Temple University, Philadelphia, PA
| | - Michael L Klein
- Institute for Computational Molecular Science, Temple University, Philadelphia, PA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ
| | - Vincenzo Carnevale
- Institute for Computational Molecular Science, Temple University, Philadelphia, PA
| |
Collapse
|
102
|
Sánchez-Lara E, Treviño S, Sánchez-Gaytán BL, Sánchez-Mora E, Eugenia Castro M, Meléndez-Bustamante FJ, Méndez-Rojas MA, González-Vergara E. Decavanadate Salts of Cytosine and Metformin: A Combined Experimental-Theoretical Study of Potential Metallodrugs Against Diabetes and Cancer. Front Chem 2018; 6:402. [PMID: 30333969 PMCID: PMC6176007 DOI: 10.3389/fchem.2018.00402] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/20/2018] [Indexed: 01/15/2023] Open
Abstract
Cytosine, a DNA and RNA building-block, and Metformin, the most widely prescribed drug for the treatment of Type 2 Diabetes mellitus were made to react separately with ammonium or sodium metavanadates in acidic aqueous solutions to obtain two polyoxovanadate salts with a 6:1 ratio of cation-anion. Thus, compounds [HCyt]6[V10O28]·4H2O, 1 and [HMetf]6[V10O28]·6H2O, 2 (where HCyt = Cytosinium cation, [C4H6N3O]+ and HMetf = Metforminium cation, [C4H12N5]+) were obtained and characterized by elemental analysis, single crystal X-ray diffraction, vibrational spectroscopy (IR and Raman), solution 51V-NMR, thermogravimetric analysis (TGA-DTGA), as well as, theoretical methods. Both compounds crystallized in P1 ¯ space group with Z' = 1/2, where the anionic charge of the centrosymmetric ion [V10O28]6- is balanced by six Cytosinium and six Metforminium counterions, respectively. Compound 1 is stabilized by π-π stacking interactions coming from the aromatic rings of HCyt cations, as denoted by close contacts of 3.63 Å. On the other hand, guanidinium moieties from the non-planar HMetf in Compound 2 interact with decavanadate μ2-O atoms via N-H···O hydrogen bonds. The vibrational spectroscopic data of both IR and Raman spectra show that the dominant bands in the 1000-450 cm-1 range are due to the symmetric and asymmetric ν(V-O) vibrational modes. In solution, 51V-NMR experiments of both compounds show that polyoxovanadate species are progressively transformed into the monomeric, dimeric and tetrameric oxovanadates. The thermal stability behavior suggests a similar molecular mechanism regarding the loss of water molecules and the decomposition of the organic counterions. Yet, no changes were observed in the TGA range of 540-580°C due to the stability of the [V10O28]6- fragment. Dispersion-corrected density functional theory (DFT-D) calculations were carried out to model the compounds in aqueous phase using a polarized continuum model calculation. Optimized structures were obtained and the main non-covalent interactions were characterized. Biological activities of these compounds are also under investigation. The combination of two therapeutic agents opens up a window toward the generation of potential metalopharmaceuticals with new and exciting pharmacological properties.
Collapse
Affiliation(s)
- Eduardo Sánchez-Lara
- Centro de Química del Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Samuel Treviño
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Brenda L. Sánchez-Gaytán
- Centro de Química del Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Enrique Sánchez-Mora
- Instituto de Física “Luis Rivera Terrazas”, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - María Eugenia Castro
- Centro de Química del Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | | | - Miguel A. Méndez-Rojas
- Departamento de Ciencias Químico-Biológicas, Universidad de las Américas Puebla, Puebla, Mexico
| | - Enrique González-Vergara
- Centro de Química del Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| |
Collapse
|
103
|
Huang Y, Winkler PA, Sun W, Lü W, Du J. Architecture of the TRPM2 channel and its activation mechanism by ADP-ribose and calcium. Nature 2018; 562:145-149. [PMID: 30250252 DOI: 10.1038/s41586-018-0558-4] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/03/2018] [Indexed: 12/16/2022]
Abstract
Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, non-selective cation channel that has an essential role in diverse physiological processes such as core body temperature regulation, immune response and apoptosis1-4. TRPM2 is polymodal and can be activated by a wide range of stimuli1-7, including temperature, oxidative stress and NAD+-related metabolites such as ADP-ribose (ADPR). Its activation results in both Ca2+ entry across the plasma membrane and Ca2+ release from lysosomes8, and has been linked to diseases such as ischaemia-reperfusion injury, bipolar disorder and Alzheimer's disease9-11. Here we report the cryo-electron microscopy structures of the zebrafish TRPM2 in the apo resting (closed) state and in the ADPR/Ca2+-bound active (open) state, in which the characteristic NUDT9-H domains hang underneath the MHR1/2 domain. We identify an ADPR-binding site located in the bi-lobed structure of the MHR1/2 domain. Our results provide an insight into the mechanism of activation of the TRPM channel family and define a framework for the development of therapeutic agents to treat neurodegenerative diseases and temperature-related pathological conditions.
Collapse
Affiliation(s)
- Yihe Huang
- Van Andel Research Institute, Grand Rapids, MI, USA
| | | | - Weinan Sun
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA.,Janelia Research Campus, Ashburn, VA, USA
| | - Wei Lü
- Van Andel Research Institute, Grand Rapids, MI, USA.
| | - Juan Du
- Van Andel Research Institute, Grand Rapids, MI, USA.
| |
Collapse
|
104
|
Membrane protein structural biology in the era of single particle cryo-EM. Curr Opin Struct Biol 2018; 52:58-63. [PMID: 30219656 DOI: 10.1016/j.sbi.2018.08.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 05/15/2018] [Accepted: 08/29/2018] [Indexed: 11/22/2022]
Abstract
In the past few years, significant technological breakthroughs in single particle cryo-electron microscopy enabled a 'resolution revolution' of this technique. It also changed structural biology in an unprecedented way. For many biological macromolecules, obtaining well-ordered crystals of suitable size is no longer a prerequisite for determining their atomic structures. One of the most impacted areas is the structural biology of integral membrane proteins. New structures are now determined at a rapid pace. Despite these advances, further technological developments are still required to overcome new technical challenges that face membrane protein structural biology. In this review, I attempt to discuss some of these challenges.
Collapse
|
105
|
Sierra-Valdez F, Azumaya CM, Romero LO, Nakagawa T, Cordero-Morales JF. Structure-function analyses of the ion channel TRPC3 reveal that its cytoplasmic domain allosterically modulates channel gating. J Biol Chem 2018; 293:16102-16114. [PMID: 30139744 DOI: 10.1074/jbc.ra118.005066] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/17/2018] [Indexed: 12/14/2022] Open
Abstract
The transient receptor potential ion channels support Ca2+ permeation in many organs, including the heart, brain, and kidney. Genetic mutations in transient receptor potential cation channel subfamily C member 3 (TRPC3) are associated with neurodegenerative diseases, memory loss, and hypertension. To better understand the conformational changes that regulate TRPC3 function, we solved the cryo-EM structures for the full-length human TRPC3 and its cytoplasmic domain (CPD) in the apo state at 5.8- and 4.0-Å resolution, respectively. These structures revealed that the TRPC3 transmembrane domain resembles those of other TRP channels and that the CPD is a stable module involved in channel assembly and gating. We observed the presence of a C-terminal domain swap at the center of the CPD where horizontal helices (HHs) transition into a coiled-coil bundle. Comparison of TRPC3 structures revealed that the HHs can reside in two distinct positions. Electrophysiological analyses disclosed that shortening the length of the C-terminal loop connecting the HH with the TRP helices increases TRPC3 activity and that elongating the length of the loop has the opposite effect. Our findings indicate that the C-terminal loop affects channel gating by altering the allosteric coupling between the cytoplasmic and transmembrane domains. We propose that molecules that target the HH may represent a promising strategy for controlling TRPC3-associated neurological disorders and hypertension.
Collapse
Affiliation(s)
- Francisco Sierra-Valdez
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | | | - Luis O Romero
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, .,Center for Structural Biology, and.,Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Julio F Cordero-Morales
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| |
Collapse
|
106
|
Abstract
Members of the transient receptor potential (TRP) ion channels conduct cations into cells. They mediate functions ranging from neuronally mediated hot and cold sensation to intracellular organellar and primary ciliary signaling. Here we report a cryo-electron microscopy (cryo-EM) structure of TRPC4 in its unliganded (apo) state to an overall resolution of 3.3 Å. The structure reveals a unique architecture with a long pore loop stabilized by a disulfide bond. Beyond the shared tetrameric six-transmembrane fold, the TRPC4 structure deviates from other TRP channels with a unique cytosolic domain. This unique cytosolic N-terminal domain forms extensive aromatic contacts with the TRP and the C-terminal domains. The comparison of our structure with other known TRP structures provides molecular insights into TRPC4 ion selectivity and extends our knowledge of the diversity and evolution of the TRP channels.
Collapse
|
107
|
Role of the TRPM4 Channel in Cardiovascular Physiology and Pathophysiology. Cells 2018; 7:cells7060062. [PMID: 29914130 PMCID: PMC6025450 DOI: 10.3390/cells7060062] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 12/31/2022] Open
Abstract
The transient receptor potential cation channel subfamily M member 4 (TRPM4) channel influences calcium homeostasis during many physiological activities such as insulin secretion, immune response, respiratory reaction, and cerebral vasoconstriction. This calcium-activated, monovalent, selective cation channel also plays a key role in cardiovascular pathophysiology; for example, a mutation in the TRPM4 channel leads to cardiac conduction disease. Recently, it has been suggested that the TRPM4 channel is also involved in the development of cardiac ischemia-reperfusion injury, which causes myocardial infarction. In the present review, we discuss the physiological function of the TRPM4 channel, and assess its role in cardiovascular pathophysiology.
Collapse
|
108
|
|
109
|
Hantute-Ghesquier A, Haustrate A, Prevarskaya N, Lehen'kyi V. TRPM Family Channels in Cancer. Pharmaceuticals (Basel) 2018; 11:ph11020058. [PMID: 29875336 PMCID: PMC6027338 DOI: 10.3390/ph11020058] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/28/2018] [Accepted: 06/01/2018] [Indexed: 12/11/2022] Open
Abstract
Members of the TRPM ("Melastatin") family fall into the subclass of the TRP channels having varying permeability to Ca2+ and Mg2+, with three members of the TRPM family being chanzymes, which contain C-terminal enzyme domains. The role of different TRPM members has been shown in various cancers such as prostate cancer for mostly TRPM8 and TRPM2, breast cancer for mostly TRPM2 and TRPM7, and pancreatic cancer for TRPM2/7/8 channels. The role of TRPM5 channels has been shown in lung cancer, TRPM1 in melanoma, and TRPM4 channel in prostate cancer as well. Thus, the TRPM family of channels may represent an appealing target for the anticancer therapy.
Collapse
Affiliation(s)
- Aline Hantute-Ghesquier
- Laboratory of Cell Physiology, INSERM U1003, Laboratory of Excellence Ion Channels Science and Therapeutics, Department of Biology, Faculty of Science and Technologies, University of Lille, 59650 Villeneuve d'Ascq, France.
| | - Aurélien Haustrate
- Laboratory of Cell Physiology, INSERM U1003, Laboratory of Excellence Ion Channels Science and Therapeutics, Department of Biology, Faculty of Science and Technologies, University of Lille, 59650 Villeneuve d'Ascq, France.
- FONDATION ARC, 9 rue Guy Môquet 94830 Villejuif, France.
| | - Natalia Prevarskaya
- Laboratory of Cell Physiology, INSERM U1003, Laboratory of Excellence Ion Channels Science and Therapeutics, Department of Biology, Faculty of Science and Technologies, University of Lille, 59650 Villeneuve d'Ascq, France.
| | - V'yacheslav Lehen'kyi
- Laboratory of Cell Physiology, INSERM U1003, Laboratory of Excellence Ion Channels Science and Therapeutics, Department of Biology, Faculty of Science and Technologies, University of Lille, 59650 Villeneuve d'Ascq, France.
- FONDATION ARC, 9 rue Guy Môquet 94830 Villejuif, France.
| |
Collapse
|
110
|
Ozhathil LC, Delalande C, Bianchi B, Nemeth G, Kappel S, Thomet U, Ross‐Kaschitza D, Simonin C, Rubin M, Gertsch J, Lochner M, Peinelt C, Reymond J, Abriel H. Identification of potent and selective small molecule inhibitors of the cation channel TRPM4. Br J Pharmacol 2018; 175:2504-2519. [PMID: 29579323 PMCID: PMC6002741 DOI: 10.1111/bph.14220] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/08/2018] [Accepted: 03/16/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE TRPM4 is a calcium-activated non-selective cation channel expressed in many tissues and implicated in several diseases, and has not yet been validated as a therapeutic target due to the lack of potent and selective inhibitors. We sought to discover a novel series of small-molecule inhibitors by combining in silico methods and cell-based screening assay, with sub-micromolar potency and improved selectivity from previously reported TRPM4 inhibitors. EXPERIMENTAL APPROACH Here, we developed a high throughput screening compatible assay to record TRPM4-mediated Na+ influx in cells using a Na+ -sensitive dye and used this assay to screen a small set of compounds selected by ligand-based virtual screening using previously known weakly active and non-selective TRPM4 inhibitors as seed molecules. Conventional electrophysiological methods were used to validate the potency and selectivity of the hit compounds in HEK293 cells overexpressing TRPM4 and in endogenously expressing prostate cancer cell line LNCaP. Chemical chaperone property of compound 5 was studied using Western blots and electrophysiology experiments. KEY RESULTS A series of halogenated anthranilic amides were identified with TRPM4 inhibitory properties with sub-micromolar potency and adequate selectivity. We also showed for the first time that a naturally occurring variant of TRPM4, which displays loss-of-expression and function, is rescued by the most promising compound 5 identified in this study. CONCLUSIONS AND IMPLICATIONS The discovery of compound 5, a potent and selective inhibitor of TRPM4 with an additional chemical chaperone feature, revealed new opportunities for studying the role of TRPM4 in human diseases and developing clinical drug candidates.
Collapse
Affiliation(s)
- Lijo Cherian Ozhathil
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Clémence Delalande
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Beatrice Bianchi
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Gabor Nemeth
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Sven Kappel
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Urs Thomet
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Daniela Ross‐Kaschitza
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Céline Simonin
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Matthias Rubin
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Jürg Gertsch
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Martin Lochner
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Christine Peinelt
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Jean‐Louis Reymond
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Hugues Abriel
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| |
Collapse
|
111
|
Minard A, Bauer CC, Wright DJ, Rubaiy HN, Muraki K, Beech DJ, Bon RS. Remarkable Progress with Small-Molecule Modulation of TRPC1/4/5 Channels: Implications for Understanding the Channels in Health and Disease. Cells 2018; 7:E52. [PMID: 29865154 PMCID: PMC6025525 DOI: 10.3390/cells7060052] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/21/2018] [Accepted: 05/23/2018] [Indexed: 12/12/2022] Open
Abstract
Proteins of the TRPC family can form many homo- and heterotetrameric cation channels permeable to Na⁺, K⁺ and Ca2+. In this review, we focus on channels formed by the isoforms TRPC1, TRPC4 and TRPC5. We review evidence for the formation of different TRPC1/4/5 tetramers, give an overview of recently developed small-molecule TRPC1/4/5 activators and inhibitors, highlight examples of biological roles of TRPC1/4/5 channels in different tissues and pathologies, and discuss how high-quality chemical probes of TRPC1/4/5 modulators can be used to understand the involvement of TRPC1/4/5 channels in physiological and pathophysiological processes.
Collapse
Affiliation(s)
- Aisling Minard
- School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
| | - Claudia C Bauer
- Department of Discovery and Translational Science, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK.
| | - David J Wright
- Department of Discovery and Translational Science, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK.
| | - Hussein N Rubaiy
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Hull HU6 7RX, UK.
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, 1-100 Kusumoto, Chikusa, Nagoya 464-8650, Japan.
| | - David J Beech
- Department of Discovery and Translational Science, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK.
| | - Robin S Bon
- Department of Discovery and Translational Science, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK.
| |
Collapse
|
112
|
Zhang Z, Tóth B, Szollosi A, Chen J, Csanády L. Structure of a TRPM2 channel in complex with Ca 2+ explains unique gating regulation. eLife 2018; 7:36409. [PMID: 29745897 PMCID: PMC5976436 DOI: 10.7554/elife.36409] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/09/2018] [Indexed: 11/18/2022] Open
Abstract
Transient receptor potential melastatin 2 (TRPM2) is a Ca2+-permeable cation channel required for immune cell activation, insulin secretion, and body heat control. TRPM2 is activated by cytosolic Ca2+, phosphatidyl-inositol-4,5-bisphosphate and ADP ribose. Here, we present the ~3 Å resolution electron cryo-microscopic structure of TRPM2 from Nematostella vectensis, 63% similar in sequence to human TRPM2, in the Ca2+-bound closed state. Compared to other TRPM channels, TRPM2 exhibits unique structural features that correlate with its function. The pore is larger and more negatively charged, consistent with its high Ca2+ selectivity and larger conductance. The intracellular Ca2+ binding sites are connected to the pore and cytosol, explaining the unusual dependence of TRPM2 activity on intra- and extracellular Ca2+. In addition, the absence of a post-filter motif is likely the cause of the rapid inactivation of human TRPM2. Together, our cryo-EM and electrophysiology studies provide a molecular understanding of the unique gating mechanism of TRPM2.
Collapse
Affiliation(s)
- Zhe Zhang
- Laboratory of Membrane Biophysics and Biology, The Rockefeller University, New York, United States.,Howard Hughes Medical Institute, Chevy Chase, United States
| | - Balázs Tóth
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| | - Andras Szollosi
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| | - Jue Chen
- Laboratory of Membrane Biophysics and Biology, The Rockefeller University, New York, United States.,Howard Hughes Medical Institute, Chevy Chase, United States
| | - László Csanády
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| |
Collapse
|
113
|
Fan C, Choi W, Sun W, Du J, Lü W. Structure of the human lipid-gated cation channel TRPC3. eLife 2018; 7:36852. [PMID: 29726814 PMCID: PMC5967863 DOI: 10.7554/elife.36852] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/02/2018] [Indexed: 12/25/2022] Open
Abstract
The TRPC channels are crucially involved in store-operated calcium entry and calcium homeostasis, and they are implicated in human diseases such as neurodegenerative disease, cardiac hypertrophy, and spinocerebellar ataxia. We present a structure of the full-length human TRPC3, a lipid-gated TRPC member, in a lipid-occupied, closed state at 3.3 Angstrom. TRPC3 has four elbow-like membrane reentrant helices prior to the first transmembrane helix. The TRP helix is perpendicular to, and thus disengaged from, the pore-lining S6, suggesting a different gating mechanism from other TRP subfamily channels. The third transmembrane helix S3 is remarkably long, shaping a unique transmembrane domain, and constituting an extracellular domain that may serve as a sensor of external stimuli. We identified two lipid-binding sites, one being sandwiched between the pre-S1 elbow and the S4-S5 linker, and the other being close to the ion-conducting pore, where the conserved LWF motif of the TRPC family is located.
Collapse
Affiliation(s)
- Chen Fan
- Van Andel Institute, Grand Rapids, United States
| | | | - Weinan Sun
- Vollum Institute, Portland, United States
| | - Juan Du
- Van Andel Institute, Grand Rapids, United States
| | - Wei Lü
- Van Andel Institute, Grand Rapids, United States
| |
Collapse
|
114
|
Hilton JK, Salehpour T, Sisco NJ, Rath P, Van Horn WD. Phosphoinositide-interacting regulator of TRP (PIRT) has opposing effects on human and mouse TRPM8 ion channels. J Biol Chem 2018; 293:9423-9434. [PMID: 29724821 DOI: 10.1074/jbc.ra118.003563] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 04/25/2018] [Indexed: 12/24/2022] Open
Abstract
Transient receptor potential melastatin 8 (TRPM8) is a cold-sensitive ion channel with diverse physiological roles. TRPM8 activity is modulated by many mechanisms, including an interaction with the small membrane protein phosphoinositide-interacting regulator of TRP (PIRT). Here, using comparative electrophysiology experiments, we identified species-dependent differences between the human and mouse TRPM8-PIRT complexes. We found that human PIRT attenuated human TPRM8 conductance, unlike mouse PIRT, which enhanced mouse TRPM8 conductance. Quantitative Western blot analysis demonstrates that this effect does not arise from decreased trafficking of TRPM8 to the plasma membrane. Chimeric human/mouse TRPM8 channels were generated to probe the molecular basis of the PIRT modulation, and the effect was recapitulated in a pore domain chimera, demonstrating the importance of this region for PIRT-mediated regulation of TRPM8. Moreover, recombinantly expressed and purified human TRPM8 S1-S4 domain (comprising transmembrane helices S1-S4, also known as the sensing domain, ligand-sensing domain, or voltage sensing-like domain) and full-length human PIRT were used to investigate binding between the proteins. NMR experiments, supported by a pulldown assay, indicated that PIRT binds directly and specifically to the TRPM8 S1-S4 domain. Binding became saturated as the S1-S4:PIRT mole ratio approached 1. Our results have uncovered species-specific TRPM8 modulation by PIRT. They provide evidence for a direct interaction between PIRT and the TRPM8 S1-S4 domain with a 1:1 binding stoichiometry, suggesting that a functional tetrameric TRPM8 channel has four PIRT-binding sites.
Collapse
Affiliation(s)
- Jacob K Hilton
- From the School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287.,the Virginia G. Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State University, Tempe, Arizona 85281, and.,The Magnetic Resonance Research Center, Arizona State University, Tempe, Arizona 85287
| | - Taraneh Salehpour
- From the School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287.,the Virginia G. Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State University, Tempe, Arizona 85281, and.,The Magnetic Resonance Research Center, Arizona State University, Tempe, Arizona 85287
| | - Nicholas J Sisco
- From the School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287.,the Virginia G. Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State University, Tempe, Arizona 85281, and.,The Magnetic Resonance Research Center, Arizona State University, Tempe, Arizona 85287
| | - Parthasarathi Rath
- From the School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287.,the Virginia G. Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State University, Tempe, Arizona 85281, and.,The Magnetic Resonance Research Center, Arizona State University, Tempe, Arizona 85287
| | - Wade D Van Horn
- From the School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, .,the Virginia G. Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State University, Tempe, Arizona 85281, and.,The Magnetic Resonance Research Center, Arizona State University, Tempe, Arizona 85287
| |
Collapse
|
115
|
Vinayagam D, Mager T, Apelbaum A, Bothe A, Merino F, Hofnagel O, Gatsogiannis C, Raunser S. Electron cryo-microscopy structure of the canonical TRPC4 ion channel. eLife 2018; 7:e36615. [PMID: 29717981 PMCID: PMC5951680 DOI: 10.7554/elife.36615] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 04/30/2018] [Indexed: 12/31/2022] Open
Abstract
Canonical transient receptor channels (TRPC) are non-selective cation channels. They are involved in receptor-operated Ca2+ signaling and have been proposed to act as store-operated channels (SOC). Their malfunction is related to cardiomyopathies and their modulation by small molecules has been shown to be effective against renal cancer cells. The molecular mechanism underlying the complex activation and regulation is poorly understood. Here, we report the electron cryo-microscopy structure of zebrafish TRPC4 in its unliganded (apo), closed state at an overall resolution of 3.6 Å. The structure reveals the molecular architecture of the cation conducting pore, including the selectivity filter and lower gate. The cytoplasmic domain contains two key hubs that have been shown to interact with modulating proteins. Structural comparisons with other TRP channels give novel insights into the general architecture and domain organization of this superfamily of channels and help to understand their function and pharmacology.
Collapse
Affiliation(s)
| | - Thomas Mager
- Department of Biophysical ChemistryMax Planck Institute of BiophysicsFrankfurt am MainGermany
| | - Amir Apelbaum
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Arne Bothe
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Felipe Merino
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Oliver Hofnagel
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Christos Gatsogiannis
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Stefan Raunser
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| |
Collapse
|
116
|
Agosto MA, Anastassov IA, Robichaux MA, Wensel TG. A Large Endoplasmic Reticulum-Resident Pool of TRPM1 in Retinal ON-Bipolar Cells. eNeuro 2018; 5:ENEURO.0143-18.2018. [PMID: 30027108 PMCID: PMC6051591 DOI: 10.1523/eneuro.0143-18.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 12/22/2022] Open
Abstract
The chemical signal of light onset, a decrease in glutamate release from rod and cone photoreceptors, is processed by a postsynaptic G protein signaling cascade in ON-bipolar cells (BPCs). The metabotropic glutamate receptor mGluR6, along with other cascade elements, is localized synaptically at the BPC dendritic tips. The effector ion channel protein transient receptor potential melastatin-1 (TRPM1), in contrast, is located not only at the dendritic tips but also in BPC bodies and axons. Little is known about the intracellular localization of TRPM1, or its trafficking route to the dendritic tip plasma membrane. Recombinant TRPM1 expressed in mammalian cells colocalized with endoplasmic reticulum (ER) markers, with little or none detected at the plasma membrane. In mouse retina, somatic TRPM1 was similarly intracellular, and not at the plasma membrane. Labeling of ER membranes by expression of a fluorescent marker showed that in BPCs the ER extends into axons and dendrites, but not dendritic tips. In cell bodies, TRPM1 colocalized with the ER, and not with the Golgi apparatus. Fluorescence protease protection (FPP) assays with TRPM1-GFP fusions in heterologous cells revealed that the N and C termini are both accessible to the cytoplasm, consistent with the transmembrane domain topology of related TRP channels. These results indicate that the majority of TRPM1 is present in the ER, from which it can potentially be transported to the dendritic tips as needed for ON light responses. The excess of ER-resident TRPM1 relative to the amount needed at the dendritic tips suggests a potential new function for TRPM1 in the ER.
Collapse
Affiliation(s)
- Melina A. Agosto
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Ivan A. Anastassov
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Michael A. Robichaux
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Theodore G. Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| |
Collapse
|
117
|
Structure of the receptor-activated human TRPC6 and TRPC3 ion channels. Cell Res 2018; 28:746-755. [PMID: 29700422 DOI: 10.1038/s41422-018-0038-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/22/2018] [Accepted: 04/02/2018] [Indexed: 12/22/2022] Open
Abstract
TRPC6 and TRPC3 are receptor-activated nonselective cation channels that belong to the family of canonical transient receptor potential (TRPC) channels. They are activated by diacylglycerol, a lipid second messenger. TRPC6 and TRPC3 are involved in many physiological processes and implicated in human genetic diseases. Here we present the structure of human TRPC6 homotetramer in complex with a newly identified high-affinity inhibitor BTDM solved by single-particle cryo-electron microscopy to 3.8 Å resolution. We also present the structure of human TRPC3 at 4.4 Å resolution. These structures show two-layer architectures in which the bell-shaped cytosolic layer holds the transmembrane layer. Extensive inter-subunit interactions of cytosolic domains, including the N-terminal ankyrin repeats and the C-terminal coiled-coil, contribute to the tetramer assembly. The high-affinity inhibitor BTDM wedges between the S5-S6 pore domain and voltage sensor-like domain to inhibit channel opening. Our structures uncover the molecular architecture of TRPC channels and provide a structural basis for understanding the mechanism of these channels.
Collapse
|
118
|
Lau C, Hunter MJ, Stewart A, Perozo E, Vandenberg JI. Never at rest: insights into the conformational dynamics of ion channels from cryo-electron microscopy. J Physiol 2018; 596:1107-1119. [PMID: 29377132 PMCID: PMC5878226 DOI: 10.1113/jp274888] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 12/27/2017] [Indexed: 01/04/2023] Open
Abstract
The tightly regulated opening and closure of ion channels underlies the electrical signals that are vital for a wide range of physiological processes. Two decades ago the first atomic level view of ion channel structures led to a detailed understanding of ion selectivity and conduction. In recent years, spectacular developments in the field of cryo-electron microscopy have resulted in cryo-EM superseding crystallography as the technique of choice for determining near-atomic resolution structures of ion channels. Here, we will review the recent developments in cryo-EM and its specific application to the study of ion channel gating. We will highlight the advantages and disadvantages of the current technology and where the field is likely to head in the next few years.
Collapse
Affiliation(s)
- Carus Lau
- Victor Chang Cardiac Research InstituteDarlinghurstNSW2010Australia
- St Vincent's Clinical SchoolUniversity of NSWDarlinghurstNSW2010Australia
| | - Mark J. Hunter
- Victor Chang Cardiac Research InstituteDarlinghurstNSW2010Australia
| | - Alastair Stewart
- Victor Chang Cardiac Research InstituteDarlinghurstNSW2010Australia
- St Vincent's Clinical SchoolUniversity of NSWDarlinghurstNSW2010Australia
| | - Eduardo Perozo
- Department of Biochemistry and Molecular BiologyUniversity of ChicagoChicagoIL60637USA
| | - Jamie I. Vandenberg
- Victor Chang Cardiac Research InstituteDarlinghurstNSW2010Australia
- St Vincent's Clinical SchoolUniversity of NSWDarlinghurstNSW2010Australia
| |
Collapse
|
119
|
Bianchi B, Ozhathil LC, Medeiros-Domingo A, Gollob MH, Abriel H. Four TRPM4 Cation Channel Mutations Found in Cardiac Conduction Diseases Lead to Altered Protein Stability. Front Physiol 2018; 9:177. [PMID: 29568272 PMCID: PMC5852105 DOI: 10.3389/fphys.2018.00177] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/20/2018] [Indexed: 12/20/2022] Open
Abstract
Transient receptor potential melastatin member 4 (TRPM4), a non-selective cation channel, mediates cell membrane depolarization in immune response, insulin secretion, neurological disorders, and cancer. Pathological variants in TRPM4 gene have been linked to several cardiac phenotypes such as complete heart block (CHB), ventricular tachycardia, and Brugada syndrome (BrS). Despite recent findings regarding the functional implications of TRPM4 in cardiac diseases, the molecular and cellular mechanisms leading to altered conduction are poorly understood. In the present study, we identify and characterize four novel TRPM4 variants found in patients with CHB or ventricular fibrillation. Three of them, p.A101T, p.S1044C and a double variant p.A101T/P1204L, led to a decreased expression and function of the channel. On the contrary, the variant p.Q854R showed an increase in TRPM4 current. Recent evidence indicates that altered degradation rate of mutant proteins represents a pathogenic mechanism underlying genetic diseases. In consequence, protein turnover of WT-TRPM4 and TRPM4 variants overexpressed in HEK293 cells was analyzed using cycloheximide, an inhibitor of protein biosynthesis. Upon addition of cycloheximide, WT-TRPM4 decayed with a half-life of ~20 h, while loss-of-expression variants showed a ~30% increase in degradation rate, with a half-life close to 12 h. Together, the gain-of-expression variant showed a higher stability and a doubled half-life compared to WT-TRPM4. In conclusion, decreased or increased protein expression of several TRPM4 variants linked to cardiac conduction disorders or ventricular arrhythmias were found to be caused by altered TRPM4 half-life compared to the WT form.
Collapse
Affiliation(s)
- Beatrice Bianchi
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Lijo Cherian Ozhathil
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | | | - Michael H Gollob
- Department of Medicine, Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
| | - Hugues Abriel
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| |
Collapse
|
120
|
Abstract
Ion channels are proteins that mediate the flow of ions across cell membranes. Human genetic mutations of one type of ion channel, called hTRPM4, underlie a form of progressive familial heart block. Its distribution among many tissues, however, suggests that its functions are broad. We have solved the atomic structure of hTRPM4 to an overall resolution of 3.7 Å. The channel is composed of four identical subunits surrounding a central pore. We show the path of Na+ ions through the channel and point out aspects of the channel’s internal machinery that may affect its function. The structure will enable more directed experiments to understand the physiological function of this channel. Transient receptor potential melastatin subfamily member 4 (TRPM4) is a widely distributed, calcium-activated, monovalent-selective cation channel. Mutations in human TRPM4 (hTRPM4) result in progressive familial heart block. Here, we report the electron cryomicroscopy structure of hTRPM4 in a closed, Na+-bound, apo state at pH 7.5 to an overall resolution of 3.7 Å. Five partially hydrated sodium ions are proposed to occupy the center of the conduction pore and the entrance to the coiled-coil domain. We identify an upper gate in the selectivity filter and a lower gate at the entrance to the cytoplasmic coiled-coil domain. Intramolecular interactions exist between the TRP domain and the S4–S5 linker, N-terminal domain, and N and C termini. Finally, we identify aromatic interactions via π–π bonds and cation–π bonds, glycosylation at an N-linked extracellular site, a pore-loop disulfide bond, and 24 lipid binding sites. We compare and contrast this structure with other TRP channels and discuss potential mechanisms of regulation and gating of human full-length TRPM4.
Collapse
|
121
|
A single NaK channel conformation is not enough for non-selective ion conduction. Nat Commun 2018; 9:717. [PMID: 29459730 PMCID: PMC5818664 DOI: 10.1038/s41467-018-03179-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 01/24/2018] [Indexed: 01/15/2023] Open
Abstract
NaK and other non-selective channels are able to conduct both sodium (Na+) and potassium (K+) with equally high efficiency. In contrast to previous crystallographic results, we show that the selectivity filter (SF) of NaK in native-like lipid membranes adopts two distinct conformations that are stabilized by either Na+ or K+ ions. The atomic differences of these conformations are resolved by solid-state NMR (ssNMR) spectroscopy and molecular dynamics (MD) simulations. Besides the canonical K+ permeation pathway, we identify a side entry ion-conduction pathway for Na+ permeation unique to NaK. Moreover, under otherwise identical conditions ssNMR spectra of the K+ selective NaK mutant (NaK2K) reveal only a single conformational state. Therefore, we propose that structural plasticity within the SF and the selection of these conformations by different ions are key molecular determinants for highly efficient conduction of different ions in non-selective cation channels.
Collapse
|
122
|
Madej MG, Ziegler CM. Dawning of a new era in TRP channel structural biology by cryo-electron microscopy. Pflugers Arch 2018; 470:213-225. [PMID: 29344776 DOI: 10.1007/s00424-018-2107-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 01/03/2018] [Indexed: 12/20/2022]
Abstract
Cryo-electron microscopy (cryo-EM) permits the determination of atomic protein structures by averaging large numbers of individual projection images recorded at cryogenic temperatures-a method termed single-particle analysis. The cryo-preservation traps proteins within a thin glass-like ice layer, making literally a freeze image of proteins in solution. Projections of randomly adopted orientations are merged to reconstruct a 3D density map. While atomic resolution for highly symmetric viruses was achieved already in 2009, the development of new sensitive and fast electron detectors has enabled cryo-EM for smaller and asymmetrical proteins including fragile membrane proteins. As one of the most important structural biology methods at present, cryo-EM was awarded in October 2017 with the Nobel Prize in Chemistry. The molecular understanding of Transient-Receptor-Potential (TRP) channels has been boosted tremendously by cryo-EM single-particle analysis. Several near-atomic and atomic structures gave important mechanistic insights, e.g., into ion permeation and selectivity, gating, as well as into the activation of this enigmatic and medically important membrane protein family by various chemical and physical stimuli. Lastly, these structures have set the starting point for the rational design of TRP channel-targeted therapeutics to counteract life-threatening channelopathies. Here, we attempt a brief introduction to the method, review the latest advances in cryo-EM structure determination of TRP channels, and discuss molecular insights into the channel function based on the wealth of TRP channel cryo-EM structures.
Collapse
Affiliation(s)
- M Gregor Madej
- Department of Structural Biology, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstrasse 31, D-93053, Regensburg, Germany
| | - Christine M Ziegler
- Department of Structural Biology, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstrasse 31, D-93053, Regensburg, Germany.
| |
Collapse
|
123
|
Affiliation(s)
- Chanhyung Bae
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andres Jara-Oseguera
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kenton J. Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
124
|
Foley JF. Papers of note in
Nature
552
(7684). Sci Signal 2017. [DOI: 10.1126/scisignal.aar7665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
This week’s articles showed that enhancing a mitochondrial stress response reduced amyloid aggregation in mice; solved the structure of the ion channel TRPM4; found a role for NOTCH1 in the assembly of adherens junctions and endothelial barrier maintenance; and showed that RNA polymerase III limits life span in worms and flies.
Collapse
|